Over the past several decades, the frequency of antimicrobial resistance and its association with serious infectious diseases has increased at alarming rates. For example, in the United States, the Centers for Disease Control and Prevention estimate that roughly 1.7 million hospital-associated infections, from all types of microorganisms, including bacteria, combined, cause or contribute to 99,000 deaths each year. Nosocomial infections can cause severe pneumonia and infections of the urinary tract, bloodstream and other parts of the body. Many types are difficult to attack with antibiotics, and antibiotic resistance is spreading to bacteria that can infect people outside the hospital (see, Pollack, Andrew. “Rising Threat of Infections Unfazed by Antibiotics” New York Times, Feb. 27, 2010). This high rate of resistance increases the morbidity, mortality, and costs associated with nosocomial infections. There is a perceived need to identify novel lead series with new antibacterial modes of action.
The problem of antibacterial resistance is compounded by the existence of bacterial strains resistant to multiple antibacterials. Drug resistant infections are an increasing threat to public health, especially for seriously ill, hospitalized patients. Infections arising from multidrug resistant MRSA, Pseudomonas aeruginosa and Acinetobacter species as well as drug resistant Klebsiella pneumoniae present formidable challenges for the medical community as few treatment options remain. Unfortunately, while resistance to current therapies continues to spread, new clinical agents to treat these infections are few in number.
WO02/08224, WO02/50061, WO02/56882, WO02/96907, WO2003087098, WO2003010138, WO2003064421, WO2003064431, WO2004002992, WO2004002490, WO2004014361, WO2004041210, WO2004096982, WO2002050036, WO2004058144, WO2004087145, WO06002047, WO06014580, WO06010040, WO06017326, WO06012396, WO06017468, WO06020561, WO01/25227, WO02/40474, WO02/07572, WO2004035569, WO2004089947, WO004024712, WO004024713, WO004087647, WO2005016916, WO2005097781, WO006010831, WO004035569, WO004089947, WO06021448, WO06032466, WO06038172, WO06046552, WO06134378 WO006137485 and WO08009700 disclose quinoline, N-ethylquinolone, N-ethyl-azaquinolone, naphthyridine, morpholine, cyclohexane, piperidine and piperazine derivatives having antibacterial activity. Thus there is a need for new antibacterials, particularly antibacterials with novel mechanisms of action.